Nematic liquid crystal composition

ABSTRACT

The present invention relates to a nematic liquid crystal composition useful as an electro-optic liquid crystal display material and having a positive dielectric anisotropy (Δ∈). The liquid crystal composition has refractive index anisotropy (Δn) adjusted to a desired level, a sufficiently low viscosity (η), and a positive dielectric anisotropy (Δ∈) while degradation of the temperature range of the nematic phase is avoided by suppressing the decrease in nematic phase-isotropic liquid phase transition temperature (T ni ) and the increase in lower limit temperature of the nematic phase. The liquid crystal composition contains one or more compounds selected from compounds represented by general formula (LC0) and one or more compounds selected from a group of compounds represented by general formula (LC1) to general formula (LC5).

TECHNICAL FIELD

The present invention relates to a nematic liquid crystal compositionuseful as an electro-optic liquid crystal display material and havingpositive dielectric anisotropy (Δ∈).

BACKGROUND ART

Liquid crystal display devices are being used in watches, calculators,various measurement instruments, automobile panels, word processors,electronic organizers, printers, computers, televisions, clocks,advertising boards, etc. Typical examples of the liquid crystal displaymode include TN (twisted nematic) mode, STN (super twisted nematic)mode, a VA mode featuring vertical alignment using TFTs (thin filmtransistors), and an IPS (in-plane switching) mode/FFS mode featuringhorizontal alignment. Liquid crystal compositions used in these liquidcrystal display devices are required to be stable against externalfactors such as moisture, air, heat, and light, stay in a liquid crystalphase in a temperature range as wide as possible centered around roomtemperature, exhibit low viscosity, and operate at a low drive voltage.A liquid crystal composition is composed of several to dozens ofcompounds in order to optimize the dielectric anisotropy (Δ∈),refractive index anisotropy (Δn), and other properties for individualdisplay devices.

A vertical alignment-mode display uses a liquid crystal compositionhaving a negative Δ∈. A horizontal alignment-mode display such as a TN,STN, or IPS-mode display uses a liquid crystal composition having apositive Δ∈. In recent years, a drive mode with which a liquid crystalcomposition having a positive Δ∈ is vertically aligned under absence ofapplied voltage and an image is displayed by applying an IPS/FFS-modeelectric field has been reported and the necessity for a liquid crystalcomposition having a positive Δ∈ is increasing. Meanwhile, low-voltagedriving, high-speed response, and wide operation temperature range arerequired in all driving modes. In other words, Δ∈ that is positive andhas a large absolute value, a low viscosity (η), and a high nematicphase-isotropic liquid phase transition temperature (T_(ni)) aredesirable. Moreover, due to the setting of Δn×d, which is the product ofΔn and a cell gap (d), it is necessary to adjust the Δn of the liquidcrystal composition to be within an appropriate range according to thecell gap. In addition, since high-speed response is important inapplying a liquid crystal display device to a television or the like, aliquid crystal composition with a small γ₁ is required.

Liquid crystal compositions that use compounds having a positive Δ∈ andrepresented by formula (A-1) or (A-2) as the constitutional componentsof liquid crystal compositions have been disclosed (PTL 1 to PTL 4).However, these liquid crystal compositions do not achieve sufficientlylow viscosity.

CITATION LIST Patent Literature

PTL 1: WO96/032365

PTL 2: Japanese Unexamined Patent Application Publication No. 09-157202

PTL 3: WO98/023564

PTL 4: Japanese Unexamined Patent Application Publication No.2003-183656

SUMMARY OF INVENTION Technical Problem

An object of the present invention is to provide a liquid crystalcomposition that has refractive index anisotropy (Δn) adjusted to adesired level, a sufficiently low viscosity (η), and a positivedielectric anisotropy (Δ∈) while degradation of the temperature range ofthe nematic phase is avoided by suppressing the decrease in nematicphase-isotropic liquid phase transition temperature (T_(ni)) and theincrease in lower limit temperature of the nematic phase.

Solution to Problem

The inventors of the present invention have studied variousfluorobenzene derivatives and found that the object can be achieved bycombining specific compounds. Thus, the present invention has been made.

The present invention provides a liquid crystal composition having apositive dielectric anisotropy and containing one or more compoundsselected from compounds represented by general formula (LC0) and one ormore compounds selected from a group of compounds represented by generalformula (LC1) to general formula (LC5) and to provide a liquid crystaldisplay device that uses the liquid crystal composition.

(In the formulae, R⁰¹ represents an alkenyl group having 2 to 5 carbonatoms, R¹¹ to R⁴¹ each independently represent an alkyl group having 1to 15 carbon atoms where one or more —CH₂— in the alkyl group may eachbe substituted with —O—, —CH═CH—, —CO—, —OCO—, —COO—, —C≡C—, —CF₂O—, or—OCF₂— so long as oxygen atoms are not directly adjacent to each otherand one or more hydrogen atoms in the alkyl group may each besubstituted with a halogen, R⁵¹ and R⁵² each independently represent analkyl group having 1 to 15 carbon atoms where one or more —CH₂— in thealkyl group may each be substituted with —O—, —CH═CH—, —CO—, —OCO—,—COO—, or —C≡C— so long as oxygen atoms are not directly adjacent toeach other, and may each represent —OCF₃ or —CF₃— when A⁵¹ or A⁵³ belowrepresents a cyclohexane ring, A⁰¹ to A⁴² each independently representany one of the structures below:

(In the structures, one or more —CH₂— in the cyclohexane ring may eachbe substituted with —O— so long as oxygen atoms are not directlyadjacent to each other, one or more —CH═ in the benzene ring may each besubstituted with —N═ so long as nitrogen atoms are not directly adjacentto each other, and X⁶¹ and X⁶² each independently represent —H, —Cl, —F,—CF₃, or —OCF₃.), A⁵¹ to A⁵³ each independently represent any one of thestructures below:

(In the formulae, one or more —CH₂CH₂— in the cyclohexane ring may eachbe substituted with —CH═CH—, —CF₂O—, or —OCF₂—, and one or more —CH═ inthe benzene ring may each be substituted with —N═ so long as nitrogenatoms are not directly adjacent to each other), X⁰¹ represents ahydrogen atom or a fluorine atom, X¹¹ to X⁴³ each independentlyrepresent —H, —Cl, —F, —CF₃, or —OCF₃, Y⁰¹ to Y⁴¹ each represent —Cl,—F, —OCHF₂, —CF₃, or —OCF₃, Z⁰¹ and Z⁰² each independently represent asingle bond, —CH═CH—, —C≡C—, —CH₂CH₂—, —(CH₂)₄—, —OCF₂—, or —CF₂O—, Z³¹to Z⁴² each independently represent a single bond, —CH═CH—, —C≡C—,—CH₂CH₂—, —(CH₂)₄—, —OCF₂—, or —CF₂O—, at least one of Z³¹ and Z³² thatare present represents a group other than a single bond, Z⁵¹ and Z⁵²each independently represent a single bond, —CH═CH—, —C≡C—, —CH₂CH₂—,—(CH₂)₄—, —OCH₂—, —CH₂O—, —OCF₂—, or —CF₂O—, m⁰¹ to m⁵¹ eachindependently represent an integer of 0 to 3, m⁰¹+m⁰², m³¹+m³², andm⁴¹+m⁴² are each independently 1, 2, 3, or 4, and when a plurality ofA⁰¹, A⁰³, A²³, A³¹, A³², A⁴¹, A⁴², A⁵², Z⁰¹, Z⁰², Z³¹, Z³², Z⁴¹, Z⁴²,and/or Z⁵² are present, they may be the same or different.)

Advantageous Effects of Invention

The liquid crystal composition of the present invention is characterizedin that the absolute value of Δ∈ can be increased although Δ∈ is apositive value. Moreover, η is low, the rotational viscosity (γ₁) issmall, liquid crystal properties are excellent, and a stable liquidcrystal phase is exhibited over a wide temperature range. Moreover, theliquid crystal composition is chemically stable against heat, light,water, etc., allows low-voltage driving, and has practical use and highreliability.

DESCRIPTION OF EMBODIMENTS

A liquid crystal composition according to the invention of the presentapplication contains one or more compounds selected from compoundsrepresented by general formula (LC0) above and one or more compoundsselected from a compound group consisting of compounds represented bygeneral formulae (LC1) to (LC5). Since a liquid crystal compositioncontaining compounds represented by general formula (LC0) and compoundsrepresented by general formulae (LC1) to (LC5) exhibits a stable liquidcrystal phase even at low temperature, the liquid crystal compositioncan be regarded as a practical liquid crystal composition.

R⁰¹ in general formula (LC0) represents an alkenyl group having 2 to 5carbon atoms and is preferably selected from the groups represented byformula (R1) to formula (R5).

(In each formula, the black dot represents a bonding point to a ring.)

A compound represented by general formula (LC0) with R⁰¹ representing analkyl group having 1 to 8 carbon atoms or an alkoxy group having 1 to 8carbon atoms is preferably used in combination.

In general formula (LC1) to general formula (LC5), R¹¹ to R⁵² preferablyeach independently represent an alkyl group having 1 to 8 carbon atoms,an alkenyl group having 2 to 8 carbon atoms, or an alkoxy group having 1to 8 carbon atoms and are preferably linear. When R¹¹ to R⁵² are torepresent alkenyl groups, R¹¹ to R⁵² are preferably each selected fromthe groups represented by formula (R1) to formula (R5) above. In thecase where A⁰¹, A¹¹, A²¹, A³¹, A⁴¹, A⁵¹, and A⁵³ each represent atrans-1,4-cyclohexylene group, formula (R1), formula (R2), and formula(R4) are more preferable. It is yet more preferable to contain at leastone compound represented by general formula (LC5) with at least one ofR⁵¹ and R⁵³ representing an alkenyl group selected from thoserepresented by formula (R1) to formula (R5).

A⁰¹ to A⁴² preferably each independently represent atrans-1,4-cyclohexylene group, a 1,4-phenylene group, a3-fluoro-1,4-phenylene group, a 3,5-difluoro-1,4-phenylene group, or atetrahydropyran-2,5-diyl group. If some of A⁰¹ to A⁴² are to representtetrahydropyran-2,5-diyl groups, A⁰¹, A¹¹, A²¹, A³¹, and A⁴¹ preferablyrepresent tetrahydropyran-2,5-diyl groups.

A⁵¹ to A⁵³ preferably each independently represent atrans-1,4-cyclohexylene group, a 1,4-phenylene group, a3-fluoro-1,4-phenylene group, or a 2-fluoro-1,4-phenylene group.

Z⁰¹ and Z⁰² preferably each independently represent a single bond,—CH═CH—, —C≡C—, —CH₂CH₂—, —OCF₂—, or —CF₂O—. When one of Z⁰¹ and Z⁰²that are present represents —CH═CH—, —C≡C—, —CH₂CH₂—, —(CH₂)₄—, —OCF₂—,or —CF₂O—, the other preferably represents a single bond. Morepreferably, both Z⁰¹ and Z⁰² represent single bonds.

Z³¹ to Z⁴² preferably each independently represent a single bond,—CH═CH—, —C≡C—, —CH₂CH₂—, —OCH₂—, —CH₂O—, —OCF₂—, or —CF₂O—. When one ofZ³¹ to Z⁴² that are present represents —CH═CH—, —C≡C—, —CH₂CH₂—,—(CH₂)₄—, —OCF₂—, or —CF₂O—, the others preferably represent singlebonds.

Z⁵¹ and Z⁵² preferably each independently represent a single bond,—CH═CH—, —C≡C—, —CH₂CH₂—, —OCF₂—, or —CF₂O—. When one of Z⁵¹ and Z⁵²that are present represents —CH═CH—, —C≡C—, —CH₂CH₂—, —(CH₂)₄—, —OCH₂—,—CH₂O—, —OCF₂—, or —CF₂O—, the other preferably represents a singlebond. More preferably, both Z⁵¹ and Z⁵² represent single bonds.

X⁰¹ in general formula (LC0) particularly preferably represents F sincethe viscosity (η) can be notably decreased relative to a largedielectric anisotropy (Δ∈) or about the same level of dielectricanisotropy (Δ∈). X⁰¹ to X⁴³ preferably each independently represent H orF and X⁰¹, X²¹, X³¹, and X⁴¹ preferably each represent F.

Y⁰¹ to Y⁴¹ particularly preferably each independently represent F, CF₃,or OCF₃. While m⁰¹ to m⁵¹ can each independently represent an integer of0 to 3, m⁰¹+m⁰² is particularly preferably 1 or 2, m²¹ is particularlypreferably 0, m³¹+m³² is particularly preferably 1, 2, or 3, and m⁴¹+m⁴²is particularly preferably 1 or 2.

The liquid crystal compound represented by general formula (LC0) is morepreferably a compound represented by any one of general formulae (LC0-a)to (LC0-h) below (In the formulae, R⁰¹, A⁰¹, A⁰², A⁰³, Z⁰¹, Z⁰², X⁰¹,and Y⁰¹ are the same as those in general formula (LC0). When two or moreA⁰¹, A⁰³ and/or Z⁰¹, Z⁰² are present, they may be the same ordifferent):

The liquid crystal compound represented by general formula (LC0) is morepreferably a compound represented by a general formula selected fromgeneral formula (LC0-1) to general formula (LC0-111) below:

(In the formulae, R is the same as R⁰¹ in general formula (LC0), “—F,CF₃, OCF₃” means that Y⁰¹ each independently represent one of —F, CF₃,and OCF₃, and “(—F)” represents H or F as a substituent.) Compoundsrepresented by general formula (LC0-1) to general formula (LC0-19) areparticularly preferable since they have high dielectric anisotropy (Δ∈),notably low viscosity (η), and preferable compatibility. Compoundsrepresented by general formulae (LC0-20) to (LC0-111) are particularlypreferable since they have high dielectric anisotropy (Δ∈), relativelylow viscosity (η), and a high nematic phase-isotropic liquid phasetransition temperature (T_(ni)).

The compounds represented by general formula (LC2) are more preferablycompounds represented by general formula (LC2-1) to general formula(LC2-14) below:

(In the formulae, X²³, X²⁴, X²⁵, and X²⁶ each independently represent ahydrogen atom, Cl, F, CF₃, or OCF₃, and X²², R²¹, and Y²¹ are the sameas those in general formula (LC2).) The group of compounds representedby general formula (LC2-1) to general formula (LC2-4) and generalformula (LC2-9) to general formula (LC2-11) is yet more preferable.

The compounds represented by general formula (LC3) are more preferablycompounds represented by general formula (LC3-1) to general formula(LC3-32) below:

(In the formulae, X³³, X³⁴, X³⁵, X³⁶, X³⁷, and X³⁸ each independentlyrepresent H, Cl, F, CF₃, or OCF₃, and X³², R³¹, A³¹ Y³¹ and Z³¹ are thesame as those in general formula (LC3).) Among these, the group ofcompounds represented by general formula (LC3-5), general formula(LC3-15), and general formula (LC3-20) to general formula (LC3-32) ismore preferably used in combination with the essential component of thepresent invention represented by general formula (LC0). More preferableis a compound selected from the group of compounds represented bygeneral formula (LC3-20) and general formula (LC3-21) with X³³ and X³⁴each representing F or the group of tetrahydropyran-ring-containingcompounds represented by general formula (LC3-25), general formula(LC3-26), and general formula (LC3-30) to general formula (LC3-32).

The compounds represented by general formula (LC4) are more preferablycompounds represented by general formula (LC4-1) to general formula(LC4-23) below:

(In the formulae, X⁴⁴, X⁴⁵, X⁴⁶, and X⁴⁷ each independently represent H,Cl, F, CF₃, or OCF₃, and X⁴², X⁴³, R⁴¹, and Y⁴¹ are the same as those ingeneral formula (LC4).)Among these, the group of compounds represented by general formula(LC4-1) to general formula (LC4-3), general formula (LC4-6), generalformula (LC4-9), general formula (LC4-10), and general formula (LC4-12)to general formula (LC4-17) is preferably used in combination with theessential component of the present invention represented by generalformula (LC0). Of these, one or more compounds selected from the groupof compounds represented by general formula (LC4-9) to general formula(LC4-11) and general formula (LC4-15) to general formula (LC4-17) withX⁴⁴ and/or X⁴⁵ representing F are more preferably contained.

The compounds represented by general formula (LC5) are more preferablycompounds represented by general formula (LC5-1) to general formula(LC5-26) below:

(In the formulae, R⁵¹ and R⁵² are the same as those in general formula(LC5).) Among these, the group of compounds represented by generalformula (LC5-1) to general formula (LC5-8), general formula (LC5-14),general formula (LC5-16), and general formula (LC5-18) to generalformula (LC5-26) is particularly preferably used in combination with theessential component of the present invention represented by generalformula (LC0). At least one of R⁵¹ and R⁵² in general formula (LC5-1)and general formula (LC5-4) preferably represents an alkenyl group andmore preferably represents any one of alkenyl groups represented byformula (R1) to formula (R5) below:

It is preferable to contain one or more compounds represented by generalformula (LC5) and the content thereof is preferably 30 to 70% by massand more preferably 20% by mass to 70% by mass.

The liquid crystal composition of the present invention contains acompound represented by general formula (LC0) and a compound selectedfrom the group of compounds represented by general formula (LC1) togeneral formula (LC5). The content of the compound represented bygeneral formula (LC0) is preferably in the range of 5 to 50% by mass andmore preferably in the range of 10 to 40% by mass.

The liquid crystal composition of the present invention preferably has aviscosity η of 20 mPa·s or less at 20° C.

The liquid crystal composition of the present invention may contain oneor more optically active compounds. The optical active compound may beany compound that can twist and align liquid crystal molecules. Sincetwisting normally changes depending on temperature, plural opticallyactive compounds may be used to obtain a desired temperature dependence.In order not to adversely affect the nematic liquid crystal phasetemperature range, viscosity, and the like, it is preferable to selectand use optically active compounds that have a powerful twisting effect.Examples of such optically active compounds to be contained includeliquid crystals such as cholesteric nonanoate and compounds representedby general formula (Ch-1) to general formula (Ch-6) below:

(In the formulae, R_(c1), R_(c2), and R* each independently represent analkyl group having 1 to 15 carbon atoms where one or more —CH₂— in thealkyl group may each be substituted with —O—, —CH═CH—, —CO—, —OCO—,—COO—, —C≡C—, —CF₂O—, or —OCF₂— so long as oxygen atoms are not directlyadjacent to each other and one or more hydrogen atoms in the alkyl groupmay each be substituted with a halogen; R includes at least oneoptically active branched chain group or halogen substituent; Z_(c1) andZ_(c2) each independently represent a single bond, —CH═CH—, —C≡C—,—CH₂CH₂—, —(CH₂)₄—, —COO—, —OCO—, —OCH₂—, —CH₂O—, —OCF₂—, or —CF₂O—; D₁and D₂ each independently represent a cyclohexane ring or a benzenering, one or more —CH₂— in the cyclohexane ring may each be substitutedwith —O— so long as oxygen atoms are not directly adjacent to eachother, one or more —CH₂CH₂— in the ring may each be substituted with—CH═CH—, —CF₂O—, or —OCF₂—, one or more —CH═ in the benzene ring mayeach be substituted with —N═ so long as nitrogen atoms are not directlyadjacent to each other, and one or more hydrogen atoms in the ring mayeach be substituted with F, Cl, or CH₃; t₁ and t₂ each represent 0, 1,2, or 3; and MG*, Q_(c1), and Q_(c2), represent the followingstructures:

(In the formulae, D₃ and D₄ each represent a cyclohexane ring or abenzene ring, one or more —CH₂— in the cyclohexane ring or the benzenering may each be substituted with —O— so long as oxygen atoms are notdirectly adjacent to each other, one or more —CH₂CH₂— in the ring mayeach be substituted with —CH═CH—, —CF₂O—, or —OCF₂—, one or more —CH═ inthe benzene ring may each be substituted with —N═ so long as nitrogenatoms are not directly adjacent to each other, and one or more hydrogenatoms in the ring may be substituted with F, Cl, or CH₃.)

The liquid crystal composition of the present invention may contain oneor more polymerizable compounds and the polymerizable compounds arepreferably discotic liquid crystal compounds which have a benzenederivative, a triphenylene derivative, a truxene derivative, aphthalocyanine derivative, or a cyclohexane derivative as a core at themolecular center and linear alkyl groups, linear alkoxy groups, orsubstituted benzoyloxy groups as side chains radially substituting thecore.

To be specific, the polymerizable compounds are preferably compoundsrepresented by general formula (PC):

(In the formula, P₁ represents a polymerizable functional group, Sp₁represents a spacer group having 0 to 20 carbon atoms, Q_(p1) representsa single bond, —O—, —NH—, —NHCOO—, —OCONH—, —CH═CH—, —CO—, —COO—, —OCO—,—OCOO—, —OOCO—, —CH═CH—, —CH═CH—COO—, —OCO—CH═CH—, or —C≡C—, p₁ and p₂each independently represent 1, 2, or 3, MG_(p) represents a mesogenicgroup or a mesogenic supporting group, and R_(p1) represents a halogenatom, a cyano group, or an alkyl group having 1 to 25 carbon atoms whereone or more CH₂ groups in the alkyl group may each be substituted with—O—, —S—, —NH—, —N(CH₃)—, —CO—, —COO—, —OCO—, —OCOO—, —SCO—, —COS—, or—C≡C-so long as oxygen atoms are not directly adjacent to each other orR_(p1) may represent P₂—Sp₂-Q_(p2)- where P₂, Sp₂, and Q_(p2) arerespectively the same as P₁, Sp₁, Q_(p1).)

More preferably, the polymerizable compounds are those represented bygeneral formula (PC) with MG_(p) representing the following structure:

(In the formula, C₀₁ to C₀₃ each independently represent a 1,4-phenylenegroup, a 1,4-cyclohexylene group, a 1,4-cyclohexenyl group, atetrahydropyran-2,5-diyl group, a 1,3-dioxane-2,5-diyl group, atetrahydrothiopyran-2,5-diyl group, a 1,4-bicyclo(2,2,2)octylene group,a decahydronaphthalene-2,6-diyl group, a pyridine-2,5-diyl group, apyrimidine-2,5-diyl group, a pyradine-2,5-diyl group, a1,2,3,4-tetrahydronaphthalene-2,6-diyl group, a 2,6-naphthylene group, aphenanthrene-2,7-diyl group, a 9,10-dihydrophenanthrene-2,7-diyl group,a 1,2,3,4,4a,9,10a-octahydrophenanthrene-2,7-diyl group, or afluorene-2,7-diyl group; the 1,4-phenylene group, the1,2,3,4-tetrahydronaphthalene-2,6-diyl group, the 2,6-naphthylene group,the phenanthrene-2,7-diyl group, the 9,10-dihydrophenanthrene-2,7-diylgroup, the 1,2,3,4,4a,9,10a-octahydrophenanthrene-2,7-diyl group, andthe fluorene-2,7-diyl group may each have, as a substituent, one or moreselected from F, Cl, CF₃, OCF₃, a cyano group, an alkyl group having 1to 8 carbon atoms, an alkoxy group, an alkanoyl group, an alkanoyloxygroup, an alkenyl group having 2 to 8 carbon atoms, an alkenyloxy group,an alkenoyl group, and an alkenoyloxy group; Z_(p1) and Z_(p2) eachindependently represent —COO—, —OCO—, —CH₂CH₂—, —OCH₂—, —CH₂O—, —CH═CH—,—C≡C—, —CH═CHCOO—, —OCOCH═CH—, —CH₂CH₂COO—, —CH₂CH₂OCO—, —COOCH₂CH₂—,—OCOCH₂CH₂—, —CONH—, —NHCO—, or a single bond; and p₃ represents 0, 1,or 2).

In the case where Sp₁ and Sp₂ each independently represent an alkylenegroup, the alkylene group may be substituted with one or more halogenatoms or CN and one or more CH₂ groups present in this group may each besubstituted with —O—, —S—, —NH—, —N(CH₃)—, —CO—, —COO—, —OCO—, —OCOO—,—SCO—, —COS—, or —C≡C— so long as oxygen atoms are not directly adjacentto each other. P₁ and P₂ preferably each independently represent a groupselected from those represented by general formulae below:

(In the formulae, R_(p2) to R_(p6) each independently represent ahydrogen atom, a halogen atom, or an alkyl group having 1 to

-   -   carbon atoms.)

To be more specific, the polymerizable compounds represented by generalformula (PC) are preferably polymerizable compounds represented bygeneral formula (PC0-1) to general formula (PC0-6) below:

(In the formula, p₄ each independently represent 1, 2, or 3.) Thepolymerizable compounds represented by general formula (PC0) are morepreferably polymerizable compounds represented by more specificformulae, namely, general formula (PC1-1) to general formula (PC1-9)below:

(In the formulae, p₅ represents 0, 1, 2, 3, or 4.)

More preferable are polymerizable compounds represented by generalformula (PC) to general formula (PC1-9) with Sp₁, Sp₂, Q_(p1), andQ_(p2) all representing single bonds, polymerizable compounds with P₁and P₂ representing a group represented by formula (PC0-a), an acrylate,and/or a methacrylate, polymerizable compounds represented by generalformula (PC0-1) and general formula (PC0-2) with p₁ and p₄ satisfyingp₁+p₄=1 to 6, and polymerizable compounds represented by general formula(PC1-1) and general formula (PC1-9) with R_(p1) representing F, CF₃,OCF₃, CH₃, or OCH₃, where the number of substituents R_(p1) is 1, 2, 3,or 4.

Also preferable is a discotic liquid crystal compound represented bygeneral formula (PC) with MG_(p) representing a group represented bygeneral formula (PC1)-9.

(In the formulae, R₇ each independently represent P₁-Sp₁-Q_(p1) or asubstituent represented by general formula (PC1-e), R₈₁ and R₈₂ eachindependently represent a hydrogen atom, a halogen atom, or a methylgroup, R₈₃ represents an alkoxy group having 1 to 20 carbon atoms, andat least one of hydrogen atoms in the alkoxy group is substituted with asubstituent represented by any one of general formulae (PC0-a) to(PC0-d) above.) The amount of the polymerizable compounds used ispreferably 0.05 to 2.0% by mass.

The liquid crystal composition of the present invention containing apolymerizable compound is used to manufacture a liquid crystalcomposition through polymerizing the polymerizable compound. During thisprocess, the amount of the unpolymerized components is preferablydecreased to a desired level or less. A liquid crystal composition ofthe present invention suited for this use preferably contains a compoundhaving a biphenyl group or a terphenyl group as a partial structure ingeneral formula (LC0). More specifically, it is preferable to use 0.1 to40% by mass of at least one selected from the group of compoundsrepresented by general formula (LC0-4) to general formula (LC0-6),general formula (LC0-10) to general formula (LC0-16), and generalformula (LC0-27) to general formula (LC0-107). The compound ispreferably used in combination with a polymerizable compound selectedfrom those represented by general formula (PL1-1) to general formula(PL1-3), general formula (PC1-8), and general formula (PC1-9).

The liquid crystal composition may further contain one or moreantioxidants and one or more UV absorbers. The antioxidant is preferablyselected from those represented by general formula (E-1) and/or generalformula (E-2) below:

(In the formulae, R_(e1) represents an alkyl group having 1 to 15 carbonatoms, one or more —CH₂— in the alkyl group may each be substituted with—O—, —CH═CH—, —CO—, —OCO—, —COO—, —C≡C—, —CF₂O—, or —OCF₂— so long asoxygen atoms are not directly adjacent to each other, and one or morehydrogen atoms in the alkyl group may each be substituted with ahalogen;Z_(e1) and Z_(e2) each independently represent a single bond, —CH═CH—,—C≡C—, —CH₂CH₂—, —(CH₂)₄—, —COO—, —OCO—, —OCH₂—, —CH₂O—, —OCF₂—, or—CF₂O—; andE₁ represents a cyclohexane ring or a benzene ring, one or more —CH₂— inthe cyclohexane ring may each be substituted with —O— so long as oxygenatoms are not directly adjacent to each other, one or more —CH₂CH₂— inthe ring may each be substituted with —CH═CH—, —CF₂O—, or —OCF₂—, one ormore —CH═ in the benzene ring may each be substituted with —N═ so longas nitrogen atoms are not directly adjacent to each other, one or morehydrogen atoms in the ring may each be substituted with F, Cl, or CH₃,and q₁ represents 0, 1, 2, or 3.)

The liquid crystal composition according to the present invention can beused in liquid crystal display devices, in particular, active matrixdriving liquid crystal display devices of, for example, TN mode, OCBmode, ECB mode, IPS (including FFS electrodes) mode, or VA-IPS mode(including FFS electrodes). Here, the VA-IPS mode refers to a drivingmode in which a liquid crystal material having a positive dielectricanisotropy (Δ∈>0) is vertically aligned with respect to the substratesurface in the absence of applied voltage and liquid crystal moleculesare driven by using pixel electrodes and a common electrode arranged onthe same substrate surface. Since liquid crystal molecules align in adirection of the curved electric field generated by the pixel electrodesand the common electrode, it is easy to divide pixels into sub-areas toform a multi-domain structure and enhance response. Such a system isreferred to as EOC, VA-IPS, etc., according to Non-Patent LiteraturesProc. 13th IDW, 97 (1997), Proc. 13th IDW, 175 (1997), SID Sym. Digest,319 (1998), SID Sym. Digest, 838 (1998), SID Sym. Digest, 1085 (1998),SID Sym. Digest, 334 (2000), and Eurodisplay Proc., 142 (2009). In thepresent invention, the name “VA-IPS” is used.

In general, the threshold voltage (Vc) of the Freedericksz transitionfor TN and ECB mode is determined by the following expression:

$\begin{matrix}{{Vc} = {\frac{\pi \; d_{cell}}{d_{cell} + {\langle r_{1}\rangle}}\sqrt{\frac{K\; 11}{\Delta \; ɛ}}}} & \left\lbrack {{Math}.\mspace{14mu} 1} \right\rbrack\end{matrix}$

Vc for STN mode is determined by the following expression:

$\begin{matrix}{{Vc} = {\frac{\pi \; d_{gap}}{d_{cell} + {\langle r_{2}\rangle}}\sqrt{\frac{K\; 22}{\Delta \; ɛ}}}} & \left\lbrack {{Math}.\mspace{14mu} 2} \right\rbrack\end{matrix}$

Vc for VA mode is determined by the following expression:

$\begin{matrix}{{Vc} = {\frac{\pi \; d_{cell}}{d_{cell} + {\langle r_{3}\rangle}}\sqrt{\frac{K\; 33}{\Delta \; ɛ}}}} & \left\lbrack {{Math}.\mspace{14mu} 3} \right\rbrack\end{matrix}$

(In the expressions, Vc denotes the Freedericksz transition (V), πdenotes the circular constant, d_(cell) denotes the gap (μm) between afirst substrate and a second substrate, d_(gap) denotes the gap (μm)between the pixel electrodes and the common electrode, d_(ITO) denotesthe width (μm) of the pixel electrodes and/or the common electrode,<r1>, <r2>, and <r3> denote the extrapolation length (μm), K11 denotesthe splay elastic constant (N), K22 denotes the twist elastic constant(N), K33 denotes the bend elastic constant (N), and Δ∈ denotes thedielectric anisotropy.)

It has been found that the following mathematical expression 4 isapplicable to the present invention etc., for VA-IPS mode:

$\begin{matrix}{{Vc} \propto {\frac{d_{gap} - {\langle r^{\prime}\rangle}}{d_{ITO} + {\langle r\rangle}}\frac{\pi \; d_{cell}}{d_{cell} - {\langle r_{3}\rangle}}\sqrt{\frac{K\; 33}{{\Delta \; ɛ}}}}} & \left\lbrack {{Math}.\mspace{14mu} 4} \right\rbrack\end{matrix}$

(In the expression, Vc denotes the Freedericksz transition (V), πdenotes the circular constant, d_(cell) denotes the gap (μm) between afirst substrate and a second substrate, d_(gap) denotes the gap (μm)between the pixel electrodes and the common electrode, d_(ITO) denotesthe width (μm) of the pixel electrodes and/or the common electrode, <r>,<r′>, and <r3> denote the extrapolation length (μm), K33 denotes thebend elastic constant (N), and Δ∈ denotes the dielectric anisotropy.)Mathematical expression 4 shows that the cell structure may be designedto decrease d_(gap) as much as possible and increase d_(ITO) as much aspossible to achieve low drive voltage and that a liquid crystalcomposition having Δ∈ with a large absolute value and a low K33 may beselected as the liquid crystal composition to achieve low drive voltage.

The liquid crystal composition of the present invention can be adjustedto exhibit desirable Δ∈, K11, K33, etc. The product (Δn·d) of therefractive index anisotropy (Δn) of the liquid crystal composition andthe gap (d) between the first substrate and the second substrate of adisplay device is strongly related to viewing angle characteristics andresponse speed. Accordingly, the gap (d) tends to be as small as 3 to 4μm. The product (Δn·d) is particularly preferably 0.31 to 0.33 for theTN, ECB, and IPS (liquid crystal aligns substantially horizontal to thesubstrate surface in the absence of applied voltage) modes. For theVA-IPS mode, the product is preferably 0.20 to 0.59 and more preferably0.30 to 0.40 if the alignment is vertical with respect to the twosubstrates. Since the suitable value of the product (Δn·d) differsdepending on the mode of the display device, a liquid crystalcomposition capable of exhibiting a refractive index anisotropy (Δn) invarious different ranges, such as 0.070 to 0.110, 0.100 to 0.140, or0.130 to 0.180 is required. In order to obtain a small or relativelysmall refractive index anisotropy (Δn) from the liquid crystalcomposition of the present invention, it is preferable to use 0.1 to 80%by mass of one or more compounds selected from the group consisting ofcompounds represented by general formula (LC0-1) to general formula(LC0-3), general formula (LC0-7) to general formula (LC0-9), and generalformula (LC0-20) to general formula (LC0-30). In order to obtain a largeor relatively large refractive index anisotropy (Δn), it is preferableto use 0.1 to 60% by mass of one or more compounds selected from thegroup consisting of compounds represented by general formula (LC0-4) togeneral formula (LC0-6), general formula (LC0-10) to general formula(LC0-16), and general formula (LC0-27) to general formula (LC0-107).

For the TN and ECB modes that require the liquid crystal to alignsubstantially horizontal to the substrate surface in the absence ofapplied voltage, the tilt angle is preferably 0.5 to 7°. For the VA-IPmode that requires the liquid crystal to align substantiallyperpendicular to the substrate surface in the absence of appliedvoltage, the tilt angle is preferably 85 to 90°. In order to have theliquid crystal composition aligned in such a manner, alignment filmscomposed of polyimide (PI), polyamide, chalcone, cinnamate, cinnamoyl,or the like may be provided. The alignment films are preferably formedby using an optical alignment technology. A liquid crystal compositionof the present invention containing a compound represented by generalformula (LC0) having a partial structure in which X⁰¹ represents F canbe easily aligned along the easy axis of the alignment films and thedesired tilt angle can be easily formed.

A liquid crystal composition of the present invention containing acompound represented by general formula (PC) as the polymerizablecompound can be used to form a polymer-stabilized TN-mode, OCB-mode,ECB-mode, IPS-mode, or VA-IPS mode liquid crystal display deviceprepared by polymerizing the polymerizable compounds in the liquidcrystal composition in the presence or absence of applied voltage.

EXAMPLES

The present invention will now be described in further detail by usingExamples which do not limit the scope of the present invention. Notethat the “%” for compositions of Examples and Comparative Examples belowmeans “% by mass”.

The physical properties of the liquid crystal composition are presentedas follows:

T_(N-I): nematic phase-isotropic liquid phase transition temperature (°C.)T-n: lower limit temperature (° C.) of nematic phase∈⊥: dielectric constant in a direction perpendicular to the molecularlong axis at 25° C.Δ∈: dielectric anisotropy at 25° C.no: refractive index for ordinary rays at 25° C.Δn: refractive index anisotropy at 25° C.Vth: voltage (V) applied to a 6 μm-thick cell at which the transmittancechanges by 10% when square waves are applied at a frequency of 1 KHz at25° C.Viscosity: bulk viscosity (mPa·s) at 20° C.γ₁: rotational viscosity (mPa·s)

Compounds are abbreviated as follows:

TABLE 1 n (numeral) at terminus C_(n)H_(2n+1)— -2- —CH₂CH₂— —1O— —CH₂O——O1— —OCH₂— —V— —CO— —VO— —COO— —CFFO— —CF₂O— —F —F —Cl —Cl —CN —C≡N—OCFFF —OCF₃ —CFFF 0 —OCFF —OCHF₂ —On —OC_(n)H_(2n+1) -T- —C≡C— ndm-C_(n)H_(2n+1)—HC═CH—(CH₂)_(m−1)— -ndm —(CH₂)_(n−1)—HC═CH—C_(m)H_(2m+1)ndmO— C_(n)H_(2n+1)—HC═CH—(CH₂)_(m−1)—O— —Ondm—O—(CH₂)_(n−1)—HC═CH—C_(m)H_(2m+1)

Example 1

A liquid crystal composition prepared and physical properties thereofare shown below:

TABLE 2 1d1-Cy-Cy-3 15.0% od1-Cy-Cy-1d1 15.0 3-Cy-Cy-Ph-1 8.01-Ph—Ph1—Ph-3d0 7.0 3-Cy-Cy-Ph3—OCFFF 10.0 3-Cy-Ph—Ph3—OCFFF 5.03-Cy-Ph1—Ph3—CFFO—Ph3—F 10.0 1d1-Cy-Ph3—O1—Ph3—F 10.01d1-Cy-Ph3—O1—Ph—OCFFF 20.0 Tni 72.4 T-n −36.0 Vth 1.64 γ1 52.0 ε⊥ 3.80Δε 7.88 no 1.488 Δn 0.100 Viscosity 11.1

Comparative Example 2

A liquid crystal composition prepared and physical properties thereofare shown below:

TABLE 3 1d1-Cy-Cy-3 15.0% od1-Cy-Cy-1d1 15.0 3-Cy-Cy-Ph-1 8.01-Ph—Ph1—Ph-3d0 7.0 3-Cy-Cy-Ph3—OCFFF 10.0 3-Cy-Ph—Ph3—OCFFF 5.03-Cy-Ph1—Ph3—CFFO—Ph3—F 10.0 1d1-Cy-Ph—O1—Ph3—F 10.01d1-Cy-Ph3—1O—Ph—OCFFF 20.0 Tni 64.4 T-n −32.0 Vth 1.66 γ1 97.0 ε⊥ 3.63Δε 7.57 no 1.488 Δn 0.100 Viscosity 21.0

This liquid crystal composition does not contain a compound representedby general formula (LC0) having a -Ph3-OCH₂— partial structure disclosedin this application. Although Example 1 has a larger dielectricanisotropy (Δ∈) and a high nematic phase-isotropic liquid phasetransition temperature (T_(ni)), Example 1 has viscosity substantiallylower than that of Comparative Example 1, and small γ₁. This shows thatthe combination of the present invention has outstanding benefits.

Example 3

A liquid crystal composition prepared and physical properties thereofare shown below:

TABLE 4 Compound Example 2 0d1-Cy-Cy-3 5.0% 1d1-Cy-Cy-2 10.0 1d1-Cy-Cy-310.0 3-Cy-Cy-2 5.0 3-Cy-Cy-Ph3—OCFFF 5.0 3-Cy-Ph—Ph3—OCFFF 5.03-Cy-Cy-CFFO—Ph3—F 5.0 3-Cy-Ph1—Ph3—CFFO—Ph3—F 5.0 1d1-Cy-Ph3—O1—Ph3—F5.0 1d1-Cy-Ph3—O1—Ph—OCFFF 5.0 0d1-Cy-Ph3—O1—Ph3—F 5.00d1-Cy-Ph3—O1—Ph—OCFFF 5.0 1d1-Cy-Cy-Ph3—O1—Ph3—F 5.00d1-Cy-Ph1—Ph3—O1—Ph3—F 5.0 0d1-Cy-Ph1—Ph3—O1—Ph—OCFFF 5.00d1-Cy-Ph1—Ph3—O1—Ph3—OCFFF 5.0 3-Cy-Ph3—O1—Ph—OCFFF 5.03-Cy-Cy-Ph3—O1Ph3—F 5.0 Tni 71.0 T-n −38.0 Vth 1.42 γ1 67.0 ε⊥ 4.08 Δε9.82 no 1.486 Δn 0.089 Viscosity 12.1

Example 4

A liquid crystal composition prepared and physical properties thereofare shown below:

TABLE 5 0d1-Cy-Cy-3 15.0% 1d1-Cy-Cy-2 15.0 1d1-Cy-Cy-3 10.0od1-Cy-Cy-1d1 12.0 3-Cy-Cy-2 3.0 1d1-Cy-Ph3—O1—Ph—OCFFF 5.01d1-Cy-Cy-Ph3—O1—Ph3—F 8.0 0d1-Cy-Ph1—Ph3—O1—Ph—OCFFF 8.00d1-Cy-Ph1—Ph3—O1—Ph3—OCFFF 7.0 3-Cy-Ph3—O1—Ph—OCFFF 10.03-Cy-Cy-Ph3—O1Ph3—F 7.0 Tni 73.4 T-n −32.0 Vth 1.89 γ1 43.0 ε⊥ 3.41 Δε5.74 no 1.484 Δn 0.075 Viscosity 8.5

Example 4

A liquid crystal composition prepared and physical properties thereofare shown below:

TABLE 6 0d1-Cy-Cy-3 15.0% 1d1-Cy-Cy-2 15.0 1d1-Cy-Cy-3 10.0od1-Cy-Cy-1d1 10.0 3-Cy-Cy-2 5.0 3-Cy-Cy-Ph-1 5.0 1d1-Cy-Ph3—O1—Ph3—F5.0 1d1-Cy-Cy-Ph3—O1—Ph3—F 10.0 0d1-Cy-Ph1—Ph3—O1—Ph—OCFFF 10.03-Cy-Ph3—O1—Ph—OCFFF 5.0 3-Cy-Cy-Ph3—O1Ph3—F 10.0 Tni 80.8 T-n −31.0 Vth2.02 γ1 53.0 ε⊥ 3.34 Δε 5.06 no 1.482 Δn 0.069 Viscosity 9.5

Example 5

A liquid crystal composition prepared and physical properties thereofare shown below:

TABLE 7 0d1-Cy-Cy-3 10.0% 1d1-Cy-Cy-2 15.0 0d3-Cy-Cy-3 10.02-Ph—Ph1—Ph-3d0 5.0 3-Ph—Ph1—Ph3—OCFFF 5.0 3-Ph—Ph1—Ph3—CFFO—Ph3—F 5.03-Ph—Ph3—O1—Ph—OCFFF 10.0 3-Cy-Ph—Ph3—O1—Ph—OCFFF 10.00d3-Ph—Ph3—O1—Ph—OCFFF 10.0 0d1-Cy-Ph1—Ph3—O1—Ph3—F 10.00d3-Ph—Ph1—Ph3—O1—Ph3—F 10.0 Tni 72.7 T-n −33.0 Vth 1.42 γ1 68.0 ε⊥ 3.52Δε 10.02 no 1.496 Δn 0.128 Viscosity 12.9

Example 6

A liquid crystal composition prepared and physical properties thereofare shown below:

TABLE 8 1d1-Cy-Cy-2 15.0% 0d3-Cy-Cy-3 10.0 3-Cy-Ph—O2 5.0 5-Ph—Ph-1 5.02-Ph—Ph1—Ph-3d0 5.0 3-Ph—Ph1—Ph3—OCFFF 5.0 3-Ph—Ph1—Ph3—CFFO—Ph3—F 10.03-Ph—Ph3—O1—Ph—OCFFF 5.0 3-Cy-Ph—Ph3—O1—Ph—OCFFF 10.00d3-Ph—Ph3—O1—Ph—OCFFF 10.0 0d1-Cy-Ph1—Ph3—O1—Ph3—F 10.00d3-Ph—Ph1—Ph3—O1—Ph3—F 10.0 Tni 72.9 T-n −33.0 Vth 1.38 γ1 75.0 ε⊥ 3.64Δε 11.15 no 1.498 Δn 0.139 Viscosity 14.6

Example 7

A liquid crystal composition prepared and physical properties thereofare shown below:

TABLE 9 0d1-Cy-Cy-3 10.0% 1d1-Cy-Cy-2 10.0 0d3-Cy-Cy-3 15.03-Ph—Ph1—Ph3—OCFFF 5.0 3-Ph—Ph1—Ph3—CFFO—Ph3—F 10.0 3-Ph—Ph3—O1—Ph3—F5.0 3-Cy-Ph—Ph3—O1—Ph—OCFFF 15.0 3-Cy-Ph3—O1—Ph3—Ph1—F 5.03-Ph3—O1-Cy-Ph3—Ph1—F 5.0 1d1-Cy-Ph3—O1—Ph3—F 5.01d1-Cy-Ph3—O1—Ph3—OCFFF 5.0 0d1-Cy-Ph1—Ph3—O1—Ph3—F 5.00d3-Ph—Ph1—Ph3—O1—Ph3—F 5.0 Tni 72.4 T-n −36.0 Vth 1.23 γ1 79.0 ε⊥ 4.29Δε 12.98 no 1.490 Δn 0.110 Viscosity 16.7

Example 8

A liquid crystal composition prepared and physical properties thereofare shown below:

TABLE 10 0d1-Cy-Cy-3 10.0% 1d1-Cy-Cy-2 10.0 0d3-Cy-Cy-3 15.0 3-Cy-Cy-23.0 3-Cy-Cy-O1 2.0 0d1-Cy-Cy-Ph-1 8.0 2-Cy-Cy-Ph-1 7.0 3-Cy-Ph—Ph3—F 5.03-Ph—Ph1—Ph3—CFFO—Ph3—F 5.0 3-Ph—Ph3—O1—Ph3—F 5.0 3-Ph—Ph3—O1—Ph—OCFFF3.0 3-Cy-Ph—Ph3—O1—Ph—OCFFF 15.0 0d1-Cy-Ph3—O1—Ph3—F 2.01d1-Cy-Ph3—O1—Ph3—F 5.0 0d3-Ph—Ph3—O1—Ph—OCFFF 5.0 Tni 70.8 T-n −38.0Vth 1.77 γ1 57.0 ε⊥ 3.50 Δε 6.87 no 1.488 Δn 0.094 Viscosity 11.4

Example 9

A liquid crystal composition prepared and physical properties thereofare shown below:

TABLE 11 0d1-Cy-Cy-3 10.0% 1d1-Cy-Cy-2 10.0 0d3-Cy-Cy-3 10.0 3-Cy-Cy-23.0 3-Cy-Cy-O1 2.0 3-Cy-Ph—O1 2.0 3-Cy-Ph—O2 3.0 5-Ph—Ph-1 2.00d3-Ph—Ph-3d0 3.0 0d1-Cy-Cy-Ph-1 5.0 2-Cy-Cy-Ph-1 5.0 2-Ph—Ph1—Ph-3d05.0 3-Cy-Ph—Ph3—F 2.0 3-Ph—Ph1—Ph3—OCFFF 3.0 3-Ph—Ph1—Ph3—CFFO—Ph3—F 5.03-Ph—Ph3—O1—Ph—OCFFF 5.0 3-Cy-Ph—Ph3—O1—Ph—OCFFF 5.03-Ph3—O1-Cy-Ph3—Ph1—F 5.0 0d1-Cy-Ph1—Ph3—O1—Ph3—F 7.00d3-Ph—Ph1—Ph3—O1—Ph3—F 8.0 Tni 74.5 T-n −39.0 Vth 1.61 γ1 73.0 ε⊥ 3.50Δε 8.00 no 1.490 Δn 0.115 Viscosity 13.6

Example 10

A liquid crystal composition prepared and physical properties thereofare shown below:

TABLE 12 0d1-Cy-Cy-3 10.0% 1d1-Cy-Cy-2 15.0 0d3-Cy-Cy-3 10.0 3-Cy-Ph—O22.0 5-Ph—Ph-1 2.0 2-Cy-Cy-Ph-1 7.0 2-Ph—Ph1—Ph-3d0 7.0 3-Cy-Ph—Ph3—F 2.03-Ph—Ph1—Ph3—OCFFF 3.0 3-Ph—Ph1—Ph3—CFFO—Ph3—F 5.0 3-Ph—Ph3—O1—Ph3—F 2.03-Ph—Ph3—O1—Ph—OCFFF 2.0 3-Cy-Ph—Ph3—O1—Ph—OCFFF 5.03-Cy-Ph3—O1—Ph3—Ph1—F 5.0 3-Ph3—O1-Cy-Ph3—Ph1—F 5.0 0d1-Cy-Ph3—O1—Ph3—F2.0 1d1-Cy-Ph3—O1—Ph3—F 2.0 1d1-Cy-Ph3—O1—Ph3—OCFFF 2.00d3-Ph—Ph3—O1—Ph—OCFFF 2.0 0d1-Cy-Ph1—Ph3—O1—Ph3—F 5.00d3-Ph—Ph1—Ph3—O1—Ph3—F 5.0 Tni 71.1 T-n −38.0 Vth 1.53 γ1 75.0 ε⊥ 3.71Δε 9.29 no 1.491 Δn 0.112 Viscosity 14.0

As described above, the liquid crystal compositions according toExamples 2 to 10 have low viscosity and small γ₁. This shows that thecombination of the present invention has outstanding benefits.

Example 11

A vertical alignment film was formed on a first substrate that had apair of comb-shaped transparent electrodes. Another vertical alignmentfilm was formed on a second substrate that had no electrode structure.The first substrate and the second substrate were formed into an IPSempty cell having a gap spacing of 4.0 μm. The liquid crystalcomposition of Example 1 was poured into the empty cell to prepare aliquid crystal display device.

To 99% of the liquid crystal composition of Example 1, 1% of apolymerizable compound represented by formula (PC-1)-3-1 was added andhomogeneously dissolved:

As a result, a polymerizable liquid crystal composition CLC-A wasobtained. The physical properties of CLC-A were substantially the sameas physical properties of the liquid crystal composition of Example 1.

CLC-A was held in the IPS empty cell described above. The liquid crystalcell was then irradiated with ultraviolet light using a high-pressuremercury lamp through a filter that cuts off ultraviolet rays of 300 nmor less while applying 1.8 V square waves at a frequency of 1 KHz. Theirradiation was conducted for 600 seconds while adjusting theirradiation intensity at the cell surface to be 20 mW/cm². As a result,a vertical-alignment liquid crystal display device in which apolymerizable compound in the polymerizable liquid crystal compositionwas polymerized was obtained. This display deice had significantly highresponse speed compared to the liquid crystal display device formed byusing only the liquid crystal composition of Example 1.

1.-22. (canceled)
 23. A liquid crystal composition having a positivedielectric anisotropy and containing one or more compounds selected fromcompounds represented by general formula (LC0) and one or more compoundsselected from a group of compounds represented by general formula (LC1)to general formula (LC5):

(In the formulae, R^(0l) represents an alkenyl group having 2 to 5carbon atoms, R¹¹ to R⁴¹ each independently represent an alkyl grouphaving 1 to 15 carbon atoms where one or more —CH₂— in the alkyl groupmay each be substituted with —O—, —CH═CH—, —CO—, —OCO—, —COO—, —C≡C—,—CF₂O—, or —OCF₂— so long as oxygen atoms are not directly adjacent toeach other and one or more hydrogen atoms in the alkyl group may each besubstituted with a halogen, R⁵¹ and R⁵² each independently represent analkyl group having 1 to 15 carbon atoms where one or more —CH₂— in thealkyl group may each be substituted with —O—, —CH═CH—, —CO—, —OCO—,—COO—, or —C≡C— so long as oxygen atoms are not directly adjacent toeach other and may each represent —OCF₃ or —CF₃— when A⁵¹ or A⁵³ belowrepresents a cyclohexane ring, A⁰¹ to A⁴² each independently representany one of the structures below:

(In the structures, one or more —CH₂— in the cyclohexane ring may eachbe substituted with —O— so long as oxygen atoms are not directlyadjacent to each other, one or more —CH═ in the benzene ring may each besubstituted with —N═ so long as nitrogen atoms are not directly adjacentto each other, and X⁶¹ and X⁶² each independently represent —H, —Cl, —F,—CF₃, or —OCF₃.), A⁵¹ to A⁵³ each independently represent any one of thestructures below:

(In the formulae, one or more —CH₂CH₂— in the cyclohexane ring may eachbe substituted with —CH═CH—, —CF₂O—, or —OCF₂—, and one or more —CH═ inthe benzene ring may each be substituted with —N═ so long as nitrogenatoms are not directly adjacent to each other), X⁰¹ represents ahydrogen atom or a fluorine atom, X¹¹ to X⁴³ each independentlyrepresent —H, —Cl, —F, —CF₃, or —OCF₃, Y⁰¹ to Y⁴¹ each represent —Cl,—F, —OCHF₂, —CF₃, or —OCF₃, Z⁰¹ and Z⁰² each independently represent asingle bond, —CH═CH—, —C≡C—, —CH₂CH₂—, —(CH₂)₄—, —OCF₂—, or —CF₂O—, Z³¹to Z⁴² each independently represent a single bond, —CH═CH—, —C≡C—,—CH₂CH₂—, —(CH₂)₄—, —OCF₂—, or —CF₂O—, at least one of Z³¹ and Z³² thatare present represents a group other than a single bond, Z⁵¹ and Z⁵²each independently represent a single bond, —CH═CH—, —C≡C—, —CH₂CH₂—,—(CH₂)₄—, —OCH₂—, —CH₂O—, —OCF₂—, or —CF₂O—, m⁰¹ to m⁵¹ eachindependently represent an integer of 0 to 3, m⁰¹+m⁰² is 1, 2, or 3,m³¹+m³² and m⁴¹+m⁴² are each independently 1, 2, 3, or 4, and when aplurality of A⁰¹, A⁰³, A²³, A³¹, A³², A⁴¹, A⁴², A⁵², Z⁰¹, Z⁰², Z³¹, Z³²,Z⁴¹, Z⁴², and/or Z⁵² are present, they may be the same or different.)24. The liquid crystal composition according to claim 23, wherein theliquid crystal composition contains 5 to 50% by mass of one or morecompounds represented by general formula (LC0) with R⁰¹ representing oneof (R1) to (R5) below:

(In each formula, the black dot represents a bonding point to a ring.)25. The liquid crystal composition according to claim 23, wherein X⁰¹ ingeneral formula (LC0) represents F.
 26. The liquid crystal compositionaccording to claim 23, wherein the liquid crystal composition containsone or more compounds selected from the group consisting of compoundsrepresented by general formula (LC2-1) to general formula (LC2-14) asthe compound represented by general formula (LC2):

(In the formulae, X²³, X²⁴, X²⁵, and X²⁶ each independently represent ahydrogen atom, Cl, F, CF₃, or OCF₃, and X²², R²¹, and Y²¹ are the sameas those in claim 23.)
 27. The liquid crystal composition according toclaim 23, wherein the liquid crystal composition contains one or morecompounds selected from the group consisting of compounds represented bygeneral formula (LC3-1) to general formula (LC3-32) as the compoundrepresented by general formula (LC3):

(In the formulae, X³³, X³⁴, X³⁵, X³⁶, X³⁷, and X³⁸ each independentlyrepresent H, Cl, F, CF₃, or OCF₃, and X³², R³¹, A³¹, Y³¹, and Z³¹ arethe same as those in claim 23.)
 28. The liquid crystal compositionaccording to claim 23, wherein the liquid crystal composition containsone or more compounds selected from the group consisting of compoundsrepresented by general formula (LC4-1) to general formula (LC4-23) asthe compound represented by general formula (LC4):

(In the formulae, X⁴⁴, X⁴⁵, X⁴⁶, and X⁴⁷ each independently represent H,Cl, F, CF₃, or OCF₃, and) X⁴², X⁴³, R⁴¹, and Y⁴¹ are the same as thosein claim 1.)
 29. The liquid crystal composition according to claim 23,wherein the liquid crystal composition contains one or more compoundsselected from the group consisting of compounds represented by generalformula (LC5-1) to general formula (LC5-26) as the compound representedby general formula (LC5):

(In the formulae, R⁵¹ and R⁵² are the same as those in claim 23.) 30.The liquid crystal composition according to claim 23, wherein the liquidcrystal composition contains one or more compounds in which R⁰² to R⁴¹,R⁵¹, and/or R⁵² present in general formula (LC1) to general formula(LC5) represents an alkenyl group having 2 to 5 carbon atoms.
 31. Theliquid crystal composition according to claim 23, wherein the liquidcrystal composition contains one or more compounds in which at least oneof A¹¹ to A⁴² and/or A⁵¹ to A⁵³ present in general formula (LC0) togeneral formula (LC5) represents a tetrahydropyran-2,5-diyl group. 32.The liquid crystal composition according to claim 23, wherein the liquidcrystal composition contains one or more compounds in which at least oneof Z⁰¹, Z⁰², Z³¹ to Z⁴², Z⁵¹, and Z⁵² that are present in generalformula (LC0) and general formula (LC3) to general formula (LC5)represents —CF₂O— or —OCF₂—.
 33. The liquid crystal compositionaccording to claim 23, wherein the liquid crystal composition contains30 to 70% by mass of the compounds represented by general formula (LC5)and has a bulk viscosity η of 20 mPa·s or less at 20° C.
 34. The liquidcrystal composition according to claim 23, wherein the liquid crystalcomposition contains one or more optically active compounds.
 35. Theliquid crystal composition according to claim 23, wherein the liquidcrystal composition contains one or more polymerizable compounds. 36.The liquid crystal composition according to claim 23, wherein the liquidcrystal composition contains one or more antioxidants.
 37. The liquidcrystal composition according to claim 23, wherein the liquid crystalcomposition contains one or more UV absorbers.
 38. A liquid crystaldisplay device using the liquid crystal composition according to claim23.
 39. An active matrix driving liquid crystal display device using theliquid crystal composition according to claim
 23. 40. A TN-mode,OCB-mode, ECB-mode, IPS-mode, or VA-IPS-mode liquid crystal displaydevice using the liquid crystal composition according to claim
 23. 41. Apolymer-stabilized TN-mode, OCB-mode, ECB-mode, IPS-mode, or VA-IPS-modeliquid crystal display device that uses the liquid crystal compositionaccording to claim 35 and is produced by polymerizing the polymerizablecompounds in the liquid crystal composition in the absence or presenceof applied voltage.
 42. The liquid crystal display device according toclaim 38, wherein an alignment layer that has a surface that comes intocontact with liquid crystal molecules and causes the liquid crystalmolecules to align horizontally, tilt, or align vertically includes analignment film containing at least one compound selected from polyimide(PI), polyamide, chalcone, cinnamate, and cinnamoyl.
 43. The liquidcrystal display device according to claim 42, wherein the alignmentlayer according to claim 42 further includes a polymerizable liquidcrystal compound or a polymerizable non-liquid crystal compound.
 44. Theliquid crystal display device according to claim 42, wherein analignment film prepared by an optical alignment technology is formed asthe alignment layer at the surface that comes into contact with theliquid crystal composition.